In Lighting
Fundamentals we discussed how the amount of energy necessary to
accomplish task lighting can be done with up to 70% less wattage then
other types of lamps.
Here we will focus on how the energy
efficiencies of induction grow lamps will also produce the proper
spectrums for plant growth.
While a plant benefits to a small degree with
the light wavelength or spectra that the eye sees, plants respond best
to the Ultraviolet (UV) and Infrared (IR) regions of the spectrum.
However if the spectrum is narrowly or not at all emitted by the lamp
then the plants will not develop to its fullest leafy vegetive or bulky
flowering stages that natural sunlight would have intended.
Since light plays such a critical role in a
plants successful growth it's important to have the proper quality and
quantity of light available to the plant as it needs it. Insufficient
light levels will reduce a plants overall weight and develop symptoms of
stress, decreased nodule density and smaller leaves. While too much
light can damage the plant from excessive IR heat radiation or extreme
UV radiation.
As it relates to proper light selection we'll
introduce you to the importance of two biological reactions that occur
within a plant; Photosynthesis and Photomorphogenesis
Plants absorb light by a green pigment within
the plant known as chlorophyll. When chlorophyll absorbs light and turns
it into energy it is through a chemical process within the plant called
Photosynthesis.
As Photosynthesis occurs, the wavelength
spectrum that is most beneficial to plant growth is found within certain
areas between the 380-720 nanometer range of the spectrum. The light
that is within this region is referred to as Photosynthetically Active
Radiation (PAR).
A plants spectral lighting needs will change as
it grows. Since spectrum plays an important part in the success of the
plants growth developmental biologists refer presence of these light
mediated changes that the plant absorbs through a variety of
Receptors as Photomorphogenesis.
As shown within the chart below, you can see
the average PAR ranges for most plants that should be available for
maximum chlorophyll absorption. Within these ranges plants will respond
very well to the emitted light wavelengths.
